This completely depends on the mdr agreement between seller and network/bank. It is pretty standard to see 2-3%, anything more than that is purely markup added by the seller. Anything less than that is based on transaction volume, even small business are eligible based on viable business model.
> no reliance on legacy systems like Visa, Mastercard
Legacy systems still thrive because their TPS is the highest among any payment rail. Crypto based payments is not novelty, it’s just slow due to their time taken to verify a transaction, and it’s nowhere close to what visa can do.